After Checkout fill in shipping address. On Next page you'll see a box that says "Promotion Code". Enter your voucher number into the box and apply. You will be able to see that the value of your Gift Voucher has been deducted from the total cost in the invoice. Next Page will take you to payment page for any balance amount you may have to pay.

When you have successfully placed your order, the following message will be displayed:
"Purchase Order Accepted, Thank You For Shopping With Us".